A. Field of the Invention
The present invention relates generally to compression sensors, and, more particularly to a fiber Bragg grating compression sensor system.
B. Description of the Related Art
Fiber Bragg gratings are widely used as force and temperature sensors in civil engineering. A change in the length of the grating along its long axis results in a change in the center reflection wavelength. However, fiber Bragg gratings are less sensitive to compression forces limiting their application for measurements in compression loading configurations.
Fiber optic tendon and ligament force sensors have been studied in the past. These sensors were based upon optical transmission through the fiber. They have been found to be undesirable due to the fact that it is difficult to distinguish between transmission losses in the tendon or bending of skin around the tendon. Other researchers have used multimode fiber optic sensors based on transmission losses, but not fiber Bragg gratings.
Thus, there is a need in the art for a fiber optic-based sensor that is useful in compression loading configurations.